A variety of soil-dwelling bacteria produce polyhydroxybutyrate (PHB), which serves as a source of energy and carbon under nutrient deprivation. Bacteria belonging to the genus do not generally produce PHB but are capable of using the PHB degradation product ()-3-hydroxybutyrate [()-3-HB] as a growth substrate. Essential to this utilization is the NAD-dependent dehydrogenase BdhA that converts ()-3-HB into acetoacetate, a molecule that readily enters central metabolism. Apart from the numerous studies that had focused on the biochemical characterization of BdhA, there was nothing known about the assimilation of ()-3-HB in , including the genetic regulation of expression. This study aimed to define the regulatory factors that govern or dictate the expression of the gene and ()-3-HB assimilation in PAO1. Importantly, expression of the gene was found to be specifically induced by ()-3-HB in a manner dependent on the alternative sigma factor RpoN and the enhancer-binding protein PA2005.This mode of regulation was essential for the utilization of ()-3-HB as a sole source of energy and carbon. However, non-induced levels of expression were sufficient for PAO1 to grow on ( ± )-1,3-butanediol, which is catabolized through an ()-3-HB intermediate. Because this is, we believe, the first report of an enhancer-binding protein that responds to ()-3-HB, PA2005 was named HbcR for ()-3-ydroxyutyrate atabolism egulator.


Article metrics loading...

Loading full text...

Full text loading...



  1. Akram M. (2013). A focused review of the role of ketone bodies in health and diseaseJ Med Food 16965967 [View Article][PubMed]. [Google Scholar]
  2. Anderson A.J., Dawes E.A. (1990). Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoatesMicrobiol Rev 54450472[PubMed]. [Google Scholar]
  3. Barrios H., Valderrama B., Morett E. (1999). Compilation and analysis of σ54-dependent promoter sequencesNucleic Acids Res 2743054313 [View Article][PubMed]. [Google Scholar]
  4. Brashear A., Cook G.A. (1983). A spectrophotometric, enzymatic assay for d-3-hydroxybutyrate that is not dependent on hydrazineAnal Biochem 131478482 [View Article][PubMed]. [Google Scholar]
  5. Buck M., Cannon W. (1992). Specific binding of the transcription factor sigma-54 to promoter DNANature 358422424 [View Article][PubMed]. [Google Scholar]
  6. Conway K., Boddy C.N. (2012). Sigma 54 Promoter Database. (www.sigma54.ca).
  7. Feller C., Günther R., Hofmann H.J., Grunow M. (2006). Molecular basis of substrate recognition in d-3-hydroxybutyrate dehydrogenase from Pseudomonas putidaChemBioChem 714101418 [View Article][PubMed]. [Google Scholar]
  8. Heurlier K., Dénervaud V., Pessi G., Reimmann C., Haas D. (2003). Negative control of quorum sensing by RpoN (σ54) in Pseudomonas aeruginosa PAO1J Bacteriol 18522272235 [View Article][PubMed]. [Google Scholar]
  9. Huisman G.W., de Leeuw O., Eggink G., Witholt B. (1989). Synthesis of poly-3-hydroxyalkanoates is a common feature of fluorescent pseudomonadsAppl Environ Microbiol 5519491954[PubMed]. [Google Scholar]
  10. Ito K., Nakajima Y., Ichihara E., Ogawa K., Katayama N., Nakashima K., Yoshimoto T. (2006). D-3-hydroxybutyrate dehydrogenase from Pseudomonas fragi: molecular cloning of the enzyme gene and crystal structure of the enzymeJ Mol Biol 355722733 [View Article][PubMed]. [Google Scholar]
  11. Jacobs M.A., Alwood A., Thaipisuttikul I., Spencer D., Haugen E., Ernst S., Will O., Kaul R., Raymond C., other authors. (2003). Comprehensive transposon mutant library of Pseudomonas aeruginosaProc Natl Acad Sci U S A 1001433914344 [View Article][PubMed]. [Google Scholar]
  12. Jendrossek D., Handrick R. (2002). Microbial degradation of polyhydroxyalkanoatesAnnu Rev Microbiol 56403432 [View Article][PubMed]. [Google Scholar]
  13. Jendrossek D., Schirmer A., Schlegel H.G. (1996). Biodegradation of polyhydroxyalkanoic acidsAppl Microbiol Biotechnol 46451463 [View Article][PubMed]. [Google Scholar]
  14. Kersters K., De Ley J. (1963). The oxidation of glycols by acetic acid bacteriaBiochim Biophys Acta 71311331 [View Article][PubMed]. [Google Scholar]
  15. Kovach M.E., Elzer P.H., Hill D.S., Robertson G.T., Farris M.A., Roop R.M. II, Peterson K.M. (1995). Four new derivatives of the broad-host-range cloning vector pBBR1MCS, carrying different antibiotic-resistance cassettesGene 166175176 [View Article][PubMed]. [Google Scholar]
  16. Lu J.N., Tappel R.C., Nomura C.T. (2009). Mini review: biosynthesis of poly(hydroxyalkanoates)Polym Rev (Phila Pa) 49226248 [View Article]. [Google Scholar]
  17. Lundgren B.R., Thornton W., Dornan M.H., Villegas-Peñaranda L.R., Boddy C.N., Nomura C.T. (2013). Gene PA2449 is essential for glycine metabolism and pyocyanin biosynthesis in Pseudomonas aeruginosa PAO1J Bacteriol 19520872100 [View Article][PubMed]. [Google Scholar]
  18. Lundgren B.R., Villegas-Peñaranda L.R., Harris J.R., Mottern A.M., Dunn D.M., Boddy C.N., Nomura C.T. (2014). Genetic analysis of the assimilation of C5-dicarboxylic acids in Pseudomonas aeruginosa PAO1J Bacteriol 19625432551 [View Article][PubMed]. [Google Scholar]
  19. Morett E., Segovia L. (1993). The sigma 54 bacterial enhancer-binding protein family: mechanism of action and phylogenetic relationship of their functional domainsJ Bacteriol 17560676074[PubMed]. [Google Scholar]
  20. Mountassif D., Andreoletti P., Cherkaoui-Malki M., Latruffe N., El Kebbaj M.S. (2010). Structural and catalytic properties of the d-3-hydroxybutyrate dehydrogenase from Pseudomonas aeruginosaCurr Microbiol 61712 [View Article][PubMed]. [Google Scholar]
  21. Nakajima Y., Ito K., Ichihara E., Ogawa K., Egawa T., Xu Y., Yoshimoto T. (2005). Crystallization and preliminary X-ray characterization of d-3-hydroxybutyrate dehydrogenase from Pseudomonas fragiActa Crystallogr F Struct Biol Cryst Commun 613638 [View Article][PubMed]. [Google Scholar]
  22. Paithankar K.S., Feller C., Kuettner E.B., Keim A., Grunow M., Sträter N. (2007). Cosubstrate-induced dynamics of d-3-hydroxybutyrate dehydrogenase from Pseudomonas putidaFEBS J 27457675779 [View Article][PubMed]. [Google Scholar]
  23. Pardee A.B., Jacob F., Monod J. (1959). The genetic control and cytoplasmic expression of inducibility in the synthesis of β-galactosidase by E. coliJ Mol Biol 1165178 [View Article]. [Google Scholar]
  24. Studholme D.J., Buck M. (2000). The biology of enhancer-dependent transcriptional regulation in bacteria: insights from genome sequencesFEMS Microbiol Lett 18619 [View Article][PubMed]. [Google Scholar]
  25. Tate R.L., Mehlman M.A., Tobin R.B. (1971). Metabolic fate of 1,3-butanediol in the rat: conversion to β-hydroxybutyrateJ Nutr 10117191726[PubMed]. [Google Scholar]
  26. Timm A., Steinbüchel A. (1990). Formation of polyesters consisting of medium-chain-length 3-hydroxyalkanoic acids from gluconate by Pseudomonas aeruginosa and other fluorescent pseudomonadsAppl Environ Microbiol 5633603367[PubMed]. [Google Scholar]
  27. Toyama H., Fujii A., Matsushita K., Shinagawa E., Ameyama M., Adachi O. (1995). Three distinct quinoprotein alcohol dehydrogenases are expressed when Pseudomonas putida is grown on different alcoholsJ Bacteriol 17724422450[PubMed]. [Google Scholar]
  28. Ugwu C.U., Tokiwa Y., Ichiba T. (2011). Production of (R)-3-hydroxybutyric acid by fermentation and bioconversion processes with Azohydromonas lataBioresour Technol 10267666768 [View Article][PubMed]. [Google Scholar]
  29. Winsor G.L., Lam D.K., Fleming L., Lo R., Whiteside M.D., Yu N.Y., Hancock R.E., Brinkman F.S. (2011). Pseudomonas Genome Database: improved comparative analysis and population genomics capability for Pseudomonas genomesNucleic Acids Res 39D596D600 [View Article]. [Google Scholar]

Data & Media loading...


Supplementary Data

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error